Many Shuls have a Minhag for the Chazan stand at the Bima fin the center of Shul or Kabalas Shabbos and not in his regular place up front at the Amud. Why is that?

The Minhag Yisroel Torah brings from the Vayaas Avrohom that originally there was no such Tefila as Kabalas Shabbos, and davening Friday night began with Maariv. The originators of saying the six Pirkei Tehilim that comprise Kabalas Shabbos were the great Mekubalim of Tzfas, Rav Moshe Kordevero and his brother-in-law and author of Licha Dodi Rav Shlomo Alkabetz.

At first only Yichidei Segula said Kabalas Shabbos, privately in their own homes. As the minhag gained popularity, groups called “Chevra Kabalas Shabbos” were formed and Kabalas Shabbos was said together in a side room of the Shul but not in the main Shul itself, so as not to start new minhagim in Shul. When the crowds became very large the people did not want to leave the main Shul so they said it in Shul but they had the Chazan stand in an untraditional place to differentiate it from the main Tefila.